Illustration I de a Illustration II 1. Solid line at begin- ning of activity. 2. Dotted line at end of exhalation. a Solid line at beginning of activity. Dotted line at end of exhalation. Description: Take prone position with the "small" of the back flat against the floor and the back of the neck as near the floor as possible ("bull-neck" position). Inhale deeply, retaining the original position. Exhale slowly as if blowing through a straw. While exhaling, keep the chest fixed 1m the original position forcing the air out by retracting the lower abdominal muscles. To retain the position of the chest and lower back, keep one hand on the chest and the other at the point where the small of the back comes in contact with the floor (see Illustra- tion I). Later, the exercise can be done by leaning against the wall, the heels a few inches out from the wall base {see Illustration II). After the individual gets "control" he will be able to execute the exercise without wall or floor support. This is an exceptionally good exercise in het it emphasizes a coordination of all the important muscles used in posture control. In addition to the three variations of the exercise shown in Illustration I, it is deemed